Switchboard apparatus



P 1967 A. R. CELLERINI ETAL I 3, 343,Q42

SWITCHBOARD APPARATUS v s Sheets-Sheet 1 Filed Nov. 5, 1964 8 mm. m9 H Sp 1967 A. R. CELLERINI ETAL .SWITCHBOARD APPARATUS 6 Sheets-Shet 2 FiledNov. 5, 1964 A. R. CELLERINI ETAL SWITCHBOARD APPARATUS Sept. 19, 1967Filed Nov. 5, 1964 3,343,042 1 6 Sheets-Sheet 5 S p 1967 A. R. CELLERINIETAL 3,343,042 YSWITCHBOARD APPARATUS 6 Sheets-Sheet 4 Filed Nov. 5,1964 FIG-7.

IIIIIEL I Sept. 19, 1967 A. R. CELLERINI ETAL 3,343,042

S WITCHBOARD APPARATUS Filed Nov. 5, 1964 6 Sheets-Sheet 6 United StatesPatent 3,343,042 SWITCHBOARD APPARATUS Albert R. Cellerini, Beaver, andLouis N. Ricci, Chippewa Township, Pa., assignors to WestinghouseElectric Corporation, East Pittsburgh, Pa., a corporation ofPennsylvania Filed Nov. 5, 1964, Ser. No. 409,244 8 Claims. (Cl.317-112) This invention relates generally to switchboard apparatus andmore particularly to switchboards of the type comprising plug-on typecircuit breakers. This invention also relates to plug-on type terminalconnectors.

A general object of this invention is to provide an improvedswitchboard.

Another object of this invention is to provide an improved switchboardcomprising a circuit breaker with means automatically tripping thecircuit breaker under certain predetermined conditions.

Another object of this invention is to provide an improved switchboardcomprising a plug-on type circuit breaker which improved means formoving the circuit breaker into and out of operating position on theswitchboard.

Another object of this invention is to provide an improved circuitbreaker.

Another object of this invention is to provide an improved compactlyconstructed molded-case type circuit breaker.

Another object of this invention is to provide an improved plug-on typecircuit breaker that can carry increased current with a minimum ofheating.

A further object of this invention is to provide an improved plug-ontype terminal connector.

The invention, both as to structure and operation, together withadditional objects and advantages thereof, will be best understood fromthe following detailed description when read in conjunction with theaccompanying drawings.

In said drawings:

FIGURE 1 is a side sectional View, taken generally along the line I-I ofFIG. 2, illustrating a circuit breaker constructed in accordance withprinciples of this invention;

FIG. 2 is a top plan view, with parts broken away, of the circuitbreaker seen in FIG. 1;

FIG. 3 is a sectional view of the separately enclosed trip unit of thecircuit breaker taken generally along the line III-III of FIG. 1;

FIG. 4 is a side sectional view through the center pole unit of the tripdevice of FIG. 3 with the circuit-breaker safety tripping structurebeing shown in cooperating relationship with the trip unit;

FIG. 5 is a side view of one of the contact plug-on type terminalconnectors seen in FIG. 1;

FIG. 6 is an isometric view, on a substantially smaller scale relativeto the scale of FIGS. 1-5, of a switchboard or control center comprisingat least one circuit breaker of the type disclosed in FIGS. 1 and 2, andembodying principles of this invention;

FIG. 7 is a side sectional view with parts broken away illustrating acircuit breaker in operating position in one of the compartments of theswitchboard unit seen in FIG. 6;

FIG. 8 is a partial view similar to FIG. 7 illustrating the position ofcertain parts of the structure seen in FIG. 7 when the switchboard dooris in the open position;

FIG. 9 is a sectional view, taken generally along the line IXIX of FIG.8 and illustrated on an enlarged scale relative to FIG. 8;

FIG. 10 is an end view, on an enlarged scale relative to FIG. 4 of partof the tripping structure seen in FIG. 4;

FIG. 11 is a view similar to FIG. 7 with the circuit breaker being shownin a disconnected position;

FIG. 12 is a top plan view of the carriage structure seen in FIGS. 7 and11;

FIG. 13 is an elevational view of part of the structure seen in FIG. 12which part is identified by the line XIIIXIII in FIG. 12;

FIG. 14 is an elevational view of the bell-crank lever member disclosedin FIGS. 7 and 11;

FIG. 15 is a side view of part of the structure seen in FIGS. 7 and 11With part of the disclosed terminal being rotated to a differentposition from that seen in FIGS. 7 and 11;

FIG. 16 is a plan view of one of the terminal structures seen in FIGS. 7and 11; and

FIG. 17 is a sectional view taken generally along the line XVII-XVII ofFIG. 16.

Referring to the drawings, there is shown in FIGS. 1 and 2 a circuitbreaker 3 comprising an insulating housing 5 and a three-pole circuitbreaker mechanism supported within the housing. The housing 5 comprisesa base 9 and a cover 11 both of molded insulating material.

The circuit-breaker mechanism 7 comprises an operating mechanism 13 anda trip unit 15. The circuit breaker is a three-pole circuit breakercomprising three compartments disposed in a side-by-side relationship.The center compartment is separated from each of the two outercompartments by means of a separate pair of cooperating insulatingbarriers 17 and 19 molded integrally with the circuit breaker base 9 andcover 11 respectively. At the two opposite ends of the circuit breakereach compartment is closed off by means of two insulating barriers 20that are suitably secured to the housing base and cover 11. Theremovable three-pole trip unit 15, which extends transversely across theinternal width of the circuit breaker will be hereinafter specificallydescribed. The operating mechanism 13, that is disposed in the circuitbreaker center pole unit or compartment, is a single operating mechanismfor operating the contacts of all three pole units.

Each pole unit comprises a stationary contact 21 that is fixedly securedto a rigid main conductor 23 that is secured to the base 9 by means ofbolts 25. In each pole unit, a movable contact 27 is Welded or brazed toa contact arm 29 that is pivotally mounted on a switch arm 31 by meansof a pivot pin 33. Each of the switch arms 31 is pivotally supported'atone end thereof on a separate support bracket 34 by means of a separatepivot pin 35. The switch arms 31 for all three of the pole units areconnected to move in unison by means of a common tie bar 37 that isrigidly connected to all three of the switch arms. Each of the contactarms 29 is biased about the associated pivot 33 by means of a separatespring 39 to provide contact pressure in the closed position of thecontacts.

The switch arms 31 are operated to the open and closed positions bymeans of the common operating mechanism 13. The operating mechanism 13comprises a toggle link 41 that is pivotally connected to an extension43 of the center pole switch arm 31 by means of a pivot pin 45. Thetogglelink 41 is pivotally connected to the lower end of another togglelink 47 by means of a knee pivot pin 49. The upper end of the togglelink 47 is pivotally connected to a cradle or releasable member 51 bymeans of a pivot pin 53. The cradle 51 is pivotally supported at one endthereof on the supporting bracket 34 by means of a pivot pin 57. Theother end 59 of the releasable member 51 is held in a latched positionby means of a latch member 61. The operating mechanism 13 also comprisesan inverted generally U- shaped operating lever 63 that is pivotallysupported on th bracket 34 by means of pins 65 that engage the innerends of the legs of the operating lever 63. An actuating insulatingshield 67, for substantially closing an opening 69 in the cover 11, issecured to the upper end of the operating lever 63. An insulating handleportion 71 ex tends from the shield 67 out through the opening 69 topermit manual operation of the breaker. Two overcenter springs 75 (onlyone being shown in FIG. 1) are connected under tension between the kneepin 49 of the toggle 41, 47 and the upper end of the operating lever 63.Pin means 77 are secured to the upper end of the lever 63 in order tosupport the upper ends of the springs 75.

In each pole unit, an arc-extinguishing unit 81 is provided toextinguish the are drawn between the associated contacts 21, 27. Eacharc-extinguishing unit comprises an insulating housing 83 and aplurality of magnetic steel plates 85 supported within the housing 83.The moving contact 27 moves within a generally V-shaped opening 87 (FIG.2) in the stacked plates 85, and the are drawn between the contacts 21,27 is magnetically moved to the right (FIGS. 1 and 2) into the plates 85to be extinguished during a circuit interrupting operation. Each of thearc-extinguishing units 81 is secured to the associated main conductor23 (FIG. 1) by means of four bolts 89 that are threaded into tappedopenings in the conductor 23.

At each of the three-pole units, the circuit breaker 3 is provided withtwo plug-on type terminal connectors 91 that are suitably secured atopposite ends of the circuit breaker. The plug-on type terminalconnectors 91 will be hereinafter more specifically described.

The circuit through each pole unit of the circuit breaker 3 extends fromthe right-hand (FIG. 1) terminal 91 through the conductor 23, thecontacts 21, 27, the contact arm 29, flexible conductors 93 that aresecured at one end to the contact arm 29 and at the other end to aterminal conductor 95, through the terminal conductor 95 that is securedto the base by means of a screw 97, a unitary rigid main conductor 99that is connected to the terminal conductor 95 and is secured to thebase by means of bolts 101 and 103, to the other terminal connector 91.The bolts 101 and 103 are threaded into inserts 105 in the base 9 tosecure the main conductor 99 to the base. Each of the rear-type plug-onterminal connectors 91 is connected to the associated internal conductor(23 or 99), by means of four bolts 107 that are disposed at the fourcorners of an imaginary square. Only two bolts for each of theconnectors 91 are disclosed in FIG. 1. As can be seen in FIG. 2, thesection in FIG. 1 is shown at the left in the outer pole unit and itjogs into the center pole unit in order to more clearly disclose theoperating mechanism which is a single mechanism only in the center poleunit of the circuit breaker. It is to be understood that each of thecircuits through each of the three pole units comprises the same kind ofstructure as that hereinbefore described with respect to the parts thatare illustrated in FIG. 1.

The circuit breaker 3 is disclosed in FIG. 1 in the closed or onposition. The circuit breaker, is manually operated to the open or offposition by movement of the handle 71 in a counterclockwise direction tothe 011 position. During this movement, the line of action of theovercenter spring means 75 is moved to the left to an overcenterposition to efiect a collapse of the toggle 41, 47 to pivot the switcharm 31 for the centerpole in a counterclockwise direction about theassociated pivot 35 to an open position. This movement of the, centerpole switch arm 31, because of a rigid connection of all of the switcharms- 31 by means of a rigid common tie bar 37, simultaneously moves allof the three switch arms 31 to the open position.

The circuit breaker is manually closed by reverse movement of the handle71 from the off to the on position.

This movement moves the operating lever 63 to move the line of action ofthe overcenter spring means to the right to thereby straighten thetoggle 41, 47 moving all three of the switch arms 31 simultaneously tothe closed position seen in FIG. 1.

Referring to FIGS. 1-4, the trip device 15 comprises a molded insulatingbase 113 and a molded insulating cover 115 cooperable with the base toenclose three thermal magnetic tripping means which are disposed withinthree compartments in the housing 113, 115. The compartments areseparated by means of insulating barriers 117. The trip device 15includes a molded insulating trip bar 119 that passes through suitableopenings in the barriers 117 and is common to all three of the poleunits. The trip bar 119 is pivotally supported on a bracket 121 thatextends out of the base 113 and is supported on a suitable supportingbracket 123. A separate laminated U-shaped magnetic core 125 for eachpole unit is suitably mounted in the associated compartment of the tripdevice 15 by means of bolts 127 that secure the core to the trip-unitbase 113. As can be seen in FIGS. 3 and 4, each of the main conductors99 passes through the opening in the U-shaped magnet 125 and is held inplace by means of a bolt 129. A separate movable armature 131 ispivotally supported on one leg of each of the cores 125. Each armatureis biased to an opened position'by means of a separate spring 133. A rod135 is pivotally connected to each armature 131 and a head portion 137on each rod 135 is adapted to engage and operate the trip bar 119 uponsutficient energization of the electromagnet 125, 131. Each trippingelectromagnet is energized by current flowing in the associated mainconductor 99.

The circuit breaker is tripped open instantaneously by operation of anyone of the tripping electromagnets. When one of the trippingelectroma-gnets is energized by an overload current above apredetermined value or by means of a short circuit, the armature 131 isattracted and the free end thereof is moved into engagement with theother leg of the magnet yoke 125 during which movement the rod 135 ispulled down, whereupon the head 137 of the rod 135 engages the trip bar119 causing the trip bar to rotate in a counterclockwise (FIG. 4)direction. This movement effects a releasing movement of the latch 61 todisengage the latch 61 from the cradle 51 (FIG. 1). Upon release of thecradle 51, the springs 75 act to rotate the cradle in a clockwisedirection about the pivot 57 and to collapse the toggle 41, 47 tothereby pivotally move the three switch arms 31 in a counterclockwise(FIG. 1) direction to the open position.

During the automatic opening operation the line of force of the springmeans 75 operates to move the operating lever 63 and handle 71 to anintermediate position between the on and off positions in a well knownmanner to thereby provide a visual indictaion that the circuit breakerhas been automatically tripped.

Following an automatic opening operation, it is necessary to reset andrelatch the circuit breaker mechanism before the contacts can be closed.This is effected by movement of the handle 71 to the full off position.During this movement, a pin 137 that is supported on the operating lever63, engages a shoulder 139 on the cradle 51 moving the cradle in acounterclockwise direction about the pivot 57. Near the end of thismovement, the free or latching end 59 of the cradle 51 cams the latch 61to the left against the bias of spring means (not shown) and moves belowthe latching end of the latch 61 whereupon the latch 61 is biased backto the latching position seen in FIG. 1 to relatch the cradle 51 in awell known manner. The breaker contacts are then closed in thepreviously described manner by movement of the handle to the onposition.

An adjusting mechanism is provided for adjusting the position of eacharmature 131 to provide for selection of the minimum overload currentthat will be required to instantaneously trip the circuit breaker. Theadjusting mechanism is of the type that is specifically described in thepatent to Glenn R. Thomas et al., Pat. No. 3,073,- 925. Thus, only abrief description of the adjusting mechanism is given herein. Theadjusting mechanism comprises a cam member 141 having an upper camsurface that is engaged by one end of a lever 143. The lever 143 ispivotally supported intermediate its ends on a supporting bracket 147that is attached to the yoke 125 and housing 113 by means of rivets 127.A rod 145 extends from the cam 141 to an adjusting knob 149 that passesout through a suitable opening in the trip unit housing 113, 115.Rotation of the adjusting knob 149 rotates the cam 141 to thereby pivotthe lever 143 whereupon an adjusting screw 151 on one end of the lever143 moves against the associated armature 131 to pivot the armature 131varying the magnetic air gap and therefore the minimum overload currentthat will magnetically trip the circuit breaker.

Thermal tripping means is provided to effect automatic tripping of thecircuit breaker with a time delay upon the occurrence of lower overloadcurrent conditions. The thermal tripping means comprises anotherU-shaped laminated magnet yoke 155 (FIG. 4) through which the conductor99 passes. An unlaminated magnetic bar 157 connects the upper legs ofthe magnet yoke 155. A bimetal member 159 is supported on a conductingcoil 161 that is disposed over the bar 157. Upon the occurrence of anoverload current below a predetermined value, the hysteresis losses inthe bar 157, which occur in the form of heat, will be conducted to thebimetal 159 and heat generated by eddy currents in the coil 161 will beconducted to the bimetal 159 whereupon the heated bimetal will bend tothe left (-FIG. 4) to engage an adjusting screw 165 that is supported onthe trip bar 119 to thereby rotate the trip bar 119 to effect a trippingoperation of the circuit breaker in the same general manner as washereinbefore described.

As can be seen in FIG. 1, the trip device 15 is secured to the circuitbreaker by means of bolts 101 and 103 that secure the three rig-idconductors 99 for the three pole units to the base 9. The trip device 15and conductors 99 comprise a unitary removable structure whereby thetrip units are interchangeable so that the breaker can accommodate othertrip units having different current carrying capacities. It can be seenin FIG. 3 that there are three conductors 99 extending through the tripdevice 15 for the three pole units of the trip device. Each of theconductors 99 conducts the current in the associated pole unit along thelength of the circuit breaker. In each pole unit a reartype and plug-ontype terminal connector 91 is supported on and directly connected to theassociated conductor 99 by means of four bolts 107 (only two of whichare seen in FIG. 1). In each pole unit an opening 167 is provided in thehousing base 9 to receive the terminal connector 91 that is connected tothe conductor 99. In each pole unit, the terminal connector 91 on theright (FIG. 1) passes through a separate opening 168 in the housing base9 and is connected directly to the rigid internal conductor 23 by meansof four bolts 107 (only two of the bolts 107 being seen in 'FIG. 1).

As can be seen in FIGS. 1 and 2, the circuit breaker housing 5 comprisesa front or top 181, a back or bottom 183, and side wall means comprisingtwo side walls 185 and two end walls 187. The handle 71 extends throughthe opening 69 in the front of the housing. The openings 167 and 168 inthe back of the housing permit connections between the terminalconnectors 91' and the conductors 23 and 99. The arc-extinguishing units81 extend substantially to the adjacent end wall 187.

As can be seen in FIGS. 1 and 5, each of the terminal connectors 91comprises a generally T-shaped rigid conducting support part 189. Thearm parts of the support part 189 have openings therein for receivingthe bolts 107 that are screwed into tapped openings in the conductor 99or 23 to mount the terminal structure 91 on the conductor 99 or 23 witha generally flat upper face of the terminal connector support part 189engaging a generally flat lower face of the conductor 99 or 23. The legportion 193 of the support part 189 of the terminal connector 91 extendsin a direction generally normal to the upper flat connecting surface ofthe support part 189 and this leg portion is provided with openingstherein for receiving three bolts or rivets 195 that secure a pluralityof contact members to the leg portion 193. The openings in the arm partsof the support 189 are disposed at the four corners of an imaginarysquare and the tapped openings in the conductors 99 and 23 are disposedat the four corners of an imaginary square. Thus, each of the terminalconnector structures 91 can be rotated and secured to the associatedmain conductor 99 or 23 in the same general manner as that hereinbeforedescribed.

As can be seen in FIGS. 1 and 5, a contact structure comprising twoouter contact members 201, two intermediate contact members 203 and twoinner contact members 205 is supported on the support part 193 of theconducting support 189 by means of the three rivets 195. Each of thecontact members 201, 203 and 205 comprises an elongated sheet metalconducting member having a plurality of slot portions 209 (FIG. 5)therein to form a plurality of contact fingers. As can be seen in FIG.5, each of the contact members of the specifically described contactstructure is split to provide five separate contact fingers. Each of thecontact fingers is bent over at the outer end thereof to provide ageneral-1y rounded portion forming a contact surface 213 (FIG. 1). Thereare thirty contacts or contact surfaces 213 on each of the connectors91.

The contact members 201, 203 and 205 comprise members of good conductingmaterial having good spring characteristics or resiliency. Copper andsilver are examples of good basic conducting materials, and when anyoneof these materials is alloyed in order to provide the desirableresiliency, the alloyed material can be effectively utilized as thematerial forming the contact fingers of this invention. For example, thecontact members can be formed from a beryllium copper alloy, a zirconiumcopper alloy or a cadmium copper alloy. A specific example of a suitablecontact member is a contact member formed from a beryllium copper alloyhaving the composition of about 98% copper, 1% beryllium and 0.2%nickel. The contact members may be formed by any suitable method.

The circuit breaker is shown in FIG. 11 in the disconnected position andin FIG. 7 in the connected position. In the connected position theterminal connectors 91 are connected to conducting stabs 214. It can beunderstood that as the circuit breaker is moved into the connectedposition the contact members 201 are the first to engage the stabs 214and these contact members are spread apart as they move into furtherengagement with the stabs 214; then the intermediate contact members 203engage the stabs 214 and are biased apart by the stabs and finally theinner contact 205 engage the stabs 214 to be biased apart by the stabs.The resiliency of the contact members provides a spring bias against thestabs 214 to provide good contact pressure in the connected positionseen in FIG. 7. As can be seen in FIG. 7, although the stabs 209 areprogressively wider from left to right, the contact pressure between thedifferent pairs of contact members is substantially the same because thecontact members 201 which are spread furthest apart in the connectedposition are the longest contact members and the contact members 205which are spread apart the least are the shortest contact members.

With the provision of three pairs of contact members each of whichcontact members comprises five resilient contact fingers, each of thecontact structures 91 will make contact with the associated stab 214 atthirty different contact points 213. Thus, the circuit breaker will beable to carry increased currents with less heat rise. An

advantage of the provision of three different pairs of contact membersthat progressively engage the associated stab conductor is that theforce required to initially and then progressively make contact can beless for the same amount of effective contact engagement, than thatrequired if, for example, only one row or pair of contact arms wereused.

Referring to FIG. 6, there is shown therein a control center orswitchboard 217 comprising a cabinet structure 219 having sixcompartments therein each of which compartments is provided with anopening at the front of the cabinet that is covered by means of anopenable door 221. Each of the doors 221 is pivotally mounted on thecabinet structure 219 by means of hinges 223. Each of the doors 221 isprovided with a suitable opening 225 therein for receiving the operatinghandle 71 of an enclosed circuit interrupter when the door is moved tothe closed position. Thus, the enclosed circuit interrupter or circuitbreaker 3 can be manually operated when the door 221 is in the closedposition. The switchboard 217 may have more or less than sixcompartments therein and it may be constructed in any of a number ofways that are well known in the art.

Referring to FIGS. 7 and 11, within each of the compartments of thecontrol center there is supported a back supporting plate 229 and abottom support member 231 that is suitably secured to the back plate229. The back plate 229 is a generally flat plate member having sixopenings therein for receiving six terminal structures 233 (FIGS. 16 and17). As is seen in FIGS. 16 and 17, each of the terminal structures 233comprises an insulating block 234 having an opening 235 therein. Each ofthe insulating blocks 234 is provided with four openings 237 at the fourcorners thereof for receiving four screw members that are threaded intotapped openings in the back plate 229 to mount the terminal structure onthe back plate 229. The insulating block 234 is also provided with fouropenings 241 therein for receiving four bolts 243. The stab member 214is a generally T-shaped (FIG. 17) rigid conducting member that ispositioned in a cavity 245 in the support 233 with the flat rear surfacethereof engaging the flat rear surface of a rigid generally T- shapedconductor 247. The bolts 243 rigidly secure the members 214 and 247together and support these members on the insulating block 234 which isin turn supported on the back plate 229 by means of the bolts that fixinto the openings 237 (FIG. 16). Metallic inserts 248 are provided inthe openings 241 to prevent damage to the insulating block 234 uponoperation of the bolts 243. The conductor 247 is provided with openings251 (FIG. 17) therein for receiving bolts 253 (FIGS. 7 and 11) that areused to connect the conductor 247 to one of the bus bars 255 that aresuitably supported in the switchboard enclosure (FIG. 6) in a mannerwell known in the art. As can be seen in FIG. 16, the bolts 243 aredisposed at the four corners of an imaginary square so that the members247 and 214 can be rotated 90 and still be connectable to the support233 in the same manner described. Moreover, with the openings in themembers 214 and 247 being disposed at the four corners of an imaginarysquare, either of these members 214 or 247 can be rotated 90 relative tothe other member and still be connectable to the other member in thesame manner hereinbefore described.

Referring to FIGS. 7 and 11, two side plates 259 are suitably secured toand supported on the back plate 229. The side plates 259 are spaced toreceive the circuit breaker 3 in a manner to be hereinafter described.Only one of the side plates 259 is visible in FIGS. 7 and 11', but itcan be understood that a pair of these identical side plates 259 areused to support the associated circuit breaker. Each of the side plates259 is provided with an elongated slot 261 therein that is opened at theouter end of the plate 259. The slots 261 cooperate to form a track toreceive rollers 263. The circuit breaker 3 is supported on a carriage265 (FIG. 12) that comprises two side plates 267 and two back braces 269(FIGS. lland 12). Each ofthe back braces 269 is provided with twoopenings 271 (FIG. 12) therein. Four bolts 273 (FIG. 11) that aredisposed in four openings 275 (FIGS. 11 and 12) in the insulatinghousing 5 of the circuit breaker 3 are threaded into the tapped openings271 to secure the circuit breaker 3 to the carriage 265. As can be seenin FIG. 2, the openings 275 in the housing 5 are provided in theinsulation between the pole units of the circuit breaker 3. The fourrollers 263 (FIG. 12) are suitably secured to the side plates 267.

A locking member 279 (FIG. 13) is pivotally supported intermediate theends thereof on one of the side plates 267 by means of a pivot pin 281.A spring member 283 is supported under tension between one end of thelocking member 279 and a stationary pin 284 on the side plate 267 tobias the locking member in a clockwise direction (FIGS. 7, 11 and 13)about the pivot 281. The member 279 is provided with a pin 285 thatpasses through a suitable opening 287 (FIG. 13) in the side plate 267 tolimit movement of the lever 279 in both directions. The pin 285 isprovided to cooperate with three notches 289, 291 and 293 in the sideplate 259 in a manner to be hereinafter described.

When it is desired to mount the circuit breaker 3 in the desiredposition on the switchboard, the circuit breaker structure 300, whichcomprises the molded-case circuit breaker 3 and the carriage 265, ismoved into the position seen in FIG. 11 wherein the rollers 263 areengaged in the tracks 261 in the opposite side supporting plates 259. Asthe circuit breaker structure is moved to the FIG. 11 position themembers 279, unless manually held in the unlocking position, will beautomatically moved to locking positions with the pins 285 being biasedfirst into the notches 293 and then into the notches 291. The members279 are manually operable out of the locking positions bycounterclockwise (FIG. 11) movement about the pivots 281. Each of theside plates 267 of the carriage 265 is provided with an opening 301 atthe upper end thereof to receive a hook part of a crane that may be usedto move the circuit breaker structure 300 into the position seen in FIG.11. With the circuit breaker structure 300 in the position seen in FIG.11, a bell-crank lever 305 (FIG. 14) is placed in the position seen inFIG. 11 wherein an elongated slot 307 thereof receives a pin 309 that isfixedly supported on one side plate 267 and wherein a slot portion 311at one end thereof receives a pin 313 that is fixedly supported on thesupporting side plate 259. If desired, a similar bell-crank lever 305can be simultaneously utilized at the other side of the circuit breakerstructure 300. With the bell-crank 305 in the position seen in FIG. 11,an operator manually rotates this member in a clockwise (FIG. 11)direction whereupon the circuit breaker structure 300 is moved into theconnected position seen in FIG. 7. When the circuit breaker structure300 reaches the fully connected position seen in FIG. 7, the springmember 283 will bias the lever 279 to move the pin 285 into the slot 289to thereby lock the circuit breaker structure 300 in the fully connectedposition.

When it is desired to move the circuit breaker structure 300 to adisconnected position on the switchboard, the locking lever 279 isdepressed to release the pin 285 from the slot 289. The bell crank lever305 is then rotated in a counterclockwise direction to cam the circuitbreaker structure 300 out to a fully disconnected position, and at theend of this movement, the locking pin 285 of the locking lever 279 willsnap into the slot 291 to automatically lock the circuit breakerstructure 300, in the disconnected position. The slots 293 are providedto be used as an additional locking slot when extensions (not shown) areused to elongate the tracks 261.

As can be seen in FIGS. 7, 8, 9, and 11, there is supported on thesupport 231 a safety trip structure 318 comprising a cam plate member319 that is secured to the support 231 by means of two screws 321 (FIG.9). The cam plate 319 is provided with an offset portion 323 having twobent-over portions 325 that extend upward from the support 231. Each ofthe parts 325 is provided with an opening therein, and a cam member 327is movably supported in these openings. The cam member 327 is providedwith a cam part 329 at one end thereof (FIG. 8). A spring support 331 isfixedly secured to the member 327, and a compression spring 333 isdisposed over the member 327 and biased between the member 331 and theone support part 325 to bias the cam member 327 to the left as seen inFIGS. 7, 8 and 9.

Referring to FIGS. 4 and 10, there is shown therein a tripping device341 comprising a first part 343 and a second part 345. Three insulatingsupports 347 are supported in one end of the center pole compartment ofthe circuit breaker 3. The supports 347 are supported in suitable slotsin the insulating housing parts 9 and 11. Each of the supports 347 isprovided with an opening therein, and the members 345 and 343 aredisposed within the openings to be supported on the circuit breaker. Thepart 343 has a pin member 349 thereon that engages one barrier 347 tolimit outward movement of the tripping device 341 to retain the trippingdevice 341 in position on the circuit breaker. The part 345 passesthrough a suitable opening in the housing part 115 of the trip device 15and the inner end of the part 345 is disposed adjacent the lower side ofthe trip bar 1119. A compression spring 351 is disposed over the part345 and it engages the housing part 115 and a spring support 353 to biasthe part 345 and therefore the entire tripping device 341 outward to theposition wherein the pin 349 engages the barrier 347. An adjusting screw355 engages the part 345 at one end thereof and threadedly engages thepart 343 at the other end thereof to enable adjustment of the length ofthe tripping device 341 to thereby enable adjustment of the trippingfunction that will be hereinafter described. As can be seen in FIG. 10,a roller 357 is rotatably supported at the outer end of the part 343 ona pin 359. Another roller 361 is rotatably supported on the pin 359adjacent the roller 357. Referring to FIG. 7, it will be seen that whenthe door 221 of the switchboard (FIG. 6) is in the closed position seenin FIG. 7, the door engages the outer end of the cam member 327 biasingthe cam member to the right to the position seen in FIG. 7. The spring351 (FIG. 4) biases the tripping device 341 outward to the position seenin FIG. 7. When the door 221 is moved to the open position,'the cammember 327 is released and the spring 333 (FIG. 9) biases the cam member327 to the left whereupon the cam part 329 of the member 327 engages theroller 361 (FIG. 10) camming the tripping device 34 1 (FIG. 4) inwardagainst the bias of the spring 351 during which movement the part 345engages the trip bar 119 to rotate the trip bar to a tripping positionto thereby trip the circuit breaker in the same general mannerhereinbefore described. Thus, it can be understood that the circuitbreaker 3 is automatically tripped by operation of the cam member 327when the cabinet door 221 is moved to the open position. If for anyreason the spring 333 should fail, the circuit breaker would not betripped by operation of the cam 227 when the door 221 is opened. Meansis provided to trip the breaker if an attempt is then made to move thebreaker to the disconnected position. As can be seen in FIG. 11, whenthe circuit breaker structure 300 is moved from the connected positionseen in FIG. 7 toward the disconnected position seen in FIG. 11, theroller 357 will engage the stationary cam member 319 moving to the topsurface of the cam member 319 which camming action moves the trippingdevice 341 inward against the bias of the spring 351 (FIG. 4) to effectan automatic tripping operation in the same manner hereinbeforedescribed. The cam member 319 is so positioned that the breaker will betripped before the terminal connectors 91 are moved to the disconnectedposition seen in FIG. 11.

It is to be understood that at certain installations only one of theimproved tripping cam structures 319 or 327 may be used without theother in a switchboard.

Referring to FIGS. 7, 11 and 13, it will be noted that the circuitinterrupter structure 300 will be eflectively retained in the connectedand disconnected positions by automatic operation of the manuallyreleasable locking member 279. The slot 291 serves to maintain thecircuit interrupting structure 300 in the disconnected position and alsoto stop the circuit interrupting structure in the disconnected positionto prevent accidental displacement off of the tracks 261, of thisstructure when the structure is being moved out of the connectedposition.

While the invention has been disclosed in accordance with the provisionsof the patent statutesit is to be understood that various changes in thestructural details and arrangement of parts may be made withoutdeparting from the spirit and scope of the invention.

We claim as our invention:

1. A switchboard structure comprising a cabinet having a cabinet openingtherein, bus bar means supported in said cabinet, terminal meanselectrically connected to said bus bar means, a cricuit interruptingdevice sup ported in said cabinet and comprising a terminal structureautomatically connected to said terminal means by the positioning ofsaid circuit interrupting device in said cabinet, said circuitinterrupting device comprising an insulating housing having a firstopening therein and a pair of contacts supported within said housing, anoperating member extending through said first opening and being manuallymovable to open and close said contacts, said insulating housing havinga second opening therein, a tripping device supported in said insulatinghousing and extending outward from said second opening, a trip barsupported within said insulating housing and being movable to effectautomatic opening of said contact-s, said cabinet comprising astationary cam member, and upon movement of said circuit interruptingdevice outward from said cabinet said tripping device engaging saidstationary cam member and being cammed to a position to move said tripbar to effect automatic opening of said contacts.

2. A switchboard srtucture comprising a cabinet having a cabinet openingtherein, bus bar means supported in said cabinet, terminal meanselectrically connected to said bus bar means, a circuit interruptingstructure supported in said cabinet and comprising a terminal structureautomatically connected to said terminal means by the positioning ofsaid circuit interrupting structure in the connected position, saidcircuit interrupting structure comprising an insulating housing having afirst opening therein and a pair of contacts supported within saidhousing, an operating member extending through said first opening andbeing manually movable to open and close said contacts, said insulatinghousing having a second opening therein, a tripping device supported insaid insulating housing and extending outward from said second opening,a trip bar supported within said housing and being movable to a trippingposition to effect automatic opening of said contacts, said cabinetcomprising a stationary cam member, upon movement of said circuitinterrupting structure away from said connected position toward adisconnected position wherein said terminal structure is disconnectedfrom said terminal means said tripping device engaging said stationarycam member and being cammed to a position to move said trip bar to saidtripping position, and upon movement of said circuit interruptingstructure from said disconnected position toward said connected positionsaid tripping device engaging said stationary cam member and beingcammed to a position to move said trip bar to said tripping position.

3. A switchboard structure comprising a cabinet having a cabinet openingtherein, bus bar means supported in said cabinet, a circuit interruptersupported in said cabinet in a connected position connected to said busbar means, said circuit interrupter comprising an insulating housinghaving a first opening means therein and a second opening means therein,a pair of contacts supported in said insulating housing, an operatingmember supported in said insulating housing and extending out throughsaid first opening means, said operating member being manually operableto open and close said contacts, trip means supported within saidinsulating housing, said trip means comprising a latched releasablemember releasable to effect automatic opening of said contacts and atrip bar movable to efiect release of said latched releasable member, aspring biased movable cam means supported in said cabinet, said circuitinterrupter comprising a tripping device supported in said insulatinghousing and extending out through said opening means, a cover in aclosed position closing said cabinet opening and engaging said springbiased movable cam means to maintain said spring biased movable cammeans in an inoperative position, and upon opening of said cover saidspring biased movable cam means moving automatically to engage saidtripping device to move said tripping device to a tripping position,said tripping device in moving to said tripping position moving saidtrip bar to eliect release of said latched releasable means to eifectopening of said contacts.

4. A switchboard structure according to claim 3, and said trippingdevice comprising an elongated member supported on said circuitinterrupter for rectilinear movement.

5. A switchboard structure comprising a cabinet having a cabinet openingtherein, bus bar means supported in said cabinet, terminal meanselectrically connected to said bus bar means, a circuit interruptersupported in said cabinet and comprising a terminal structureautomatically connected to said terminal means when said circuitinterrupter is positioned in said cabinet in a connected position, saidterminal structure being automatical- 1y disconnected from said terminalmeans when said circuit interrupter is moved from said connected to adisconnected position toward said cabinet opening, said circuitinterrupter comprising an insulating housing having a first openingmeans therein and a second opening means therein, a pair of contactssupported in said insulating housing, an operating member extending outfrom said first opening means and being manually movable to open andclose said contacts, said circuit interrupter comprising trip meanssupported within said insulating housing, said trip means comprising alatched releasable member releasable to effect automatic opening of saidcontacts and a trip bar movable to effect release of said latchedreleasable member, a tripping device supported in said insulatinghousing and extending out through said second opening means, saidtripping device being movable to a tripping position to move said tripbar to effect release of said latched releasable member to therebyeffect automatic opening of said contacts, a cam structure supported onsaid cabinet and combrising a stationary cam member and a movable cammember, said cabinet comprising a door closing said cabinet opening andmovable to an open position to open said cabinet opening, said door inthe closed position thereof maintaining said movable cam member in aninoperative position, when said door is moved to the open position withsaid circuit interrupter in the connected position said movable cammember being automatically released and moving to move said trippingdevice to said tripping position, said stationary cam member beingstationarily positioned such that when said circuit interrupter is movedfrom the connected position toward the dis connected position saidstationary cam member is in the path of movement of said trippingdevice, whereby when said door is opened and said movable cam memberfails to move said tripping device to said tripping position and saidcircuit interrupter is moved from the connected position toward thedisconnected position said tripping device will engage said stationarycam member and be automatically moved to said tripping position.

6. A switchboard structure according to claim 5, and said triping devicecomprising an elongated member supported on said circuit interrupter forrectilinear movement into and out of said tripping position.

7. A switchboard structure comprising a cabinet having a cabinet openingtherein, bus bar means supported in said cabinet, stationary terminalmeans supported in said cabinet and electrically connected to said busbar means, track means supported in said cabinet in proximity to saidstationary terminal means, a circuit interrupting device supported insaid cabinet and comprising support means engaging said track means,said circuit interrupting device comprising a terminal structure, saidcircuit interrupting device being movable on said track means between aconnected position wherein said terminal structure is automaticallyconnected to said terminal means and a disconnected position whereinsaid terminal structure is automatically disconnected from said terminalmeans, positioning means operable to move said circuit interruptingdevice on said track means into and out of said connected position, saidcircuit interrupting device comprisin an insulating housing having afirst opening therein and a pair of contacts supported within saidinsulating housing, an operating member extending through said firstopening and being movable to open and close said contacts, saidinsulating housing havmg a second opening therein, a tripping devicesupported in said insulating housing and extending outward from saidsecond opening, a trip bar supported within said insulating housing andbeing movable to eliect automatic opening of said contacts, a stationarycam member supported on said cabinet in the path of movement of saidtripping device which path is determined by the movement of said circuitinterrupting device on said track means from said connected positiontoward said disconnected position, and upon movement of said circuitinterrupting device on said track means outward from said cabinet fromsaid connected position to said disconnected position said trippingdevice engaging said cam member and being cammed automatically to aposition to move said trip bar to elfect automatic opening of saidcontacts before said circuit interrupting device reaches saiddisconnected position.

8. A switchboard structure according toclaim 7, and said positioningmeans comprising a bell-crank lever member manually operable to movesaid circuit interrupting device on said track means into and out ofsaid connected position.

References Cited UNITED STATES PATENTS 2,95 8,858 11/ 1960 EversoleZOO-61.62 X 3,073,925 1/ 1963 Thomas et al. 20088 3,188,412 6 /1965Netzel 200'50 3,249,708 5/1966 Johnson ZOO-61.62 X

RROBERT K. SCHAEFER, Primary Examiner.

M. GINSBURG, Assistant Examiner.

